Telephone system.



PATENTED NOV. 15, 1904.

W. R. WHITEHORNE. TELEPHONE SYSTEM.

APPLICATION FILED APR. 27, 1904.

2 8HBET8-BHEBT 1.

N0 MODEL.

WITNESSES:

PATENTED NOV. 15, 1904.

W. R. WHITEHORNE. TELEPHONE SYSTEM. APPLICATION FILED APR.27,190-1.

2 SHEETSSHEBT 1.

N0 MODEL.

P r ,yuinuun- 4 6 4/2 "Ill"!!! L/IIII PATENTED NOV. 15, 1904.

W. R. WHITEHORNE. TELEPHONE SYSTEM.

APPLICATION FILED APR. 517. 1904.

No. 775,201. v

no MODEL.

5 f I %m%%.%

UNITED STATES Patented November 15, 1904.

PATENT OFFICE TELEPHONE SYSTEM.

SPECIFICATION forming part of Letters Patent No. 775,201, dated November 15, 1904. Application filed April 27, 1904. Serial No. 205,143. (No model.)

To all whom it may concern Be it known that I, WILLIAM R. 'HI'IPE- HORNE. a subject of the residing in Bethlehem, Pennsylvania, have invented certain Improvements in Telephone Systems, of which the following is a specification.

One object of my invention is to provide a party-line telephone system with apparatus so designed and connected that when one subscriber calls or is talking the instruments of all the other subscribers on the same line are rendered inoperative and are, moreover, made to indicate, visually or otherwise, that the line on which they are connected is busy.

A further object of the invention is to so equip a telephone system that even though there be a number of subscribers on the'same line the central operator will be enabled to call or ring up any desired one of said subscribers and that without ringing the bell of any of the other instruments in the circuit. Moreover, my invention is so designed that it is impossible for any subscriber on thegiven line either to call up or to listen if any other subscriber on the same line is using his instrument.

The invention further contemplates such a combination of apparatus that the bell of an instrument called by the central operator is caused to ring by the act of said operator making the usual plug connections on the switchboard, thus obviating the necessity for the usual ringing switches, generators, &c., at central and eflecting a saving in the time required for making connections.

In addition to the above objects it is desired that the apparatus for carrying out my invention shall not only be relatively simple and inexpensive, but of such a nature that it shall not be difiicult to instal nor likely to get out of order.

These objects, together with other advantageous results which will be noted in the description, I attain as hereinafter set forth, reference being had to the accompanying drawings, in which- Figure l is a diagrammatic View illustrating the preferred arrangement of the apparatus comprising my invention, certain of the King of GreatBr-itain,

detail connections being omitted for the sake of clearness. Fig. 2 is a diagrammatic view illustrating the apparatus and connections thereof as found in each subscribe'rs instrument. Fig. 3 is a diagrammatic view showing in detail that portion of the system usually placed at the central ofiice. Fig. t is a sectional elevation of the rheostatic plugswitch shown in Fig; 3, showing the relative positions of certain of its parts; and Fig. 5 is 6 a side elevation of one of the plugs used by the central operatorin making connections between subscribers.

In carrying out my invention I employ in each telephone instrumcnta differential mag- 5 net whose windings usually have different numbers of turns and which is provided with an armature movable by the core of the magnet intoa position such that the telephone instrument will berendered inoperative, ex- 7 cept when such currents flow through the respective windings of the magnet that there is substantially no action upon the armature. and consequently no motion thereof. It is upon this device and upon the principle involved therein that the main features of. my invention are based.

In the above drawings, Fig. 2 illustrates the apparatus and connections found in each telephone instrument, said apparatus includ- 8O ing a magnet (1, having two windings a and 11 of difi'erent numbers of turns, of which the I latter winding, if, is connected permanently in series with one of the main line-wires C,

there being also. in circuit with said wire a 5 normally closed switch The second linewire (designated as main A) has in circuit with it a switch 7, (which is closed as long as the receiver 12 is on its hook 14,) a bell-controlling magnet (Z, and the second winding (4* 9 of the magnet c. There is also in circuit with the main A one winding of a transformer or induction-coil 13, whose second winding is in l circuit with the transmitter 9 of the telephone. The transmitter-circuitalso includes l a local battery f and a normally open switch 3, formed in the present instance by a pair of terminals and aportion of the receiverhook lL'this switch being closed when said hook is in its uppermost position.

iver-hool la: is so constructed as to a toe pivoted bar the switch m, so i switch will momentarily closed eiver end of d hool; rls s and will ted by the (lOWD WELICl motion of said end caused by the hanging up of; the receiver. lnrlg; the blade of the s itch 9, above retell also placed to be acted by the rec Wer- "00k in such manner that c it is undirected as therecciver end of the hook r s is made to momentarily open when said end moves downwardly.

gniteljly place? adjacent to the magnet a is be? 2: having an arm 1' which is interposeblc bets? "-n the armatu e lb of said magnet and its on so to *orevent movement of said armature, there being a spring, as shown, tending to more bar into such position. it is normally held in tic position shown in by the receivechoolc l i, being only permitted to more and lock the armature of the magnet ozwhcn s2 hook rises by the removal from it oi the receiver 12 in theggrorposition shown the metallic blade 7 said her completes the circuit of the main A through the telephone instrument independently of the receiver, while when the boot: 1% is in its uppermost position said her by engaging scontsct 17 causes said receiver to be placed in circuit with said main A. The pivoted bar 1, upon which is carried armature 16 of the magnet a, normally cont-ac with a terminal in connection with a bar 8, suppor of the bell-controlling n1sgg the armature while when said armature 16 is a r the c said int 153 in cit nit With a smell amp 6, whose second terminal l one pole of the local battery seen that said Jilj 1 is per rnsnently connected to the opposite pole of said battery.

ln 3 is shown the apparatusemployed at the central station for making the neces- Ii sery connections between the subscribers, and this consists of 2 small rheostatic plug-switch R and two circuit-breakers ,7' and h for each per c y-line.

The switch K preferably includes metallic plates 9" and respectively connected. to the main A and to one terminal of a current-genbar 1 engages eretor or, whose second terminal is grounded,

These plates p q 9 and 1 l g l l l l g supporting-base, as shown, and provided with recesses or openings 5 of such form as to receive cord-plug of the construction lndi bated at Y in Fig. 5. Such plugs consist of two metallic terminals 3/ and y", insulated from each other and connected, respectivel n to the Wires y" and 1 of a cable, said termillztfi being of such shape that the plug necessarily inserted in the holes 8, so that the terminal y always electrically connects plates 1; and 1, while the terminal 7.; always connects one of the plates e;- s", 530, with the plate It will be further noted that there a connection directly between resin A and the plate 5 for a purpose hereinafter noted.

The magnet of the circuit-breakery'is proided with a pivoted switch-armyflnormally held closed by a latch connection with the armature j of said magnet, and when so closed is in electrical contact With a terminal 3', connected to one end of the resistance 1 :1. This magnet of the circuiobrealrer is polarized, so that it will alfect its armature onl3 when current flows through its winding in one direc tion. There is also a switch 0, by which the switch formed by the barf and the terminal 3' of circuit-breakerfinely be short-circuited to permit of the establishing of n circuit independently of said breaker.

The circuit-breaker h is provided with at magnet having a Winding; connected at one end to plate q of switch K and at the other end to a terminal h, normally engaged by a switch-blade it, connected to the circuit-generator n. This bled-e held in contact with said terminal by any desired form of escapement mechanism, so that it will be released so to disengage the terminals only alter the Winding of the circuit-breaker it has been twice dcnergizcd. will be noted that the movable elements k and j of the circuit" breakers h and j are intended be returned to their normal positions sitter release by the central operator.

in Fig. 1 the abovedescribed apparatus is shown as connected in a complete telephone system which includes two two-party lines, although it'will be understood that there is no reason wl any desired practical number of subscribers could not be similarly connected on each line. The ends of the two mains A and C of each line are connected to each other and to ground, this latter connection being preferably made through c body of inductive resistance, as 'e or 0, so as to reduce as much as possible the flow 0i stray currents circuit with the terminal 20, so that the curterminal i receiver i! l ciinc in nd i.

usuailg: of dilicrv i bers of turns one winding being in one oi the iine-wircs, as A. and the ing' in scrics with l" u i ili do a inc oi her meit will. moreover, be noted that usually no two magnets connected on the same pair of iine-wircs or mains have both of their windings 5 similar numbers of turns.

ii the sn i scriber whose instrument is in- 12 from ins hook i-it in order to m the rcccr cud of sa d hook r the bar 2, causing the :LZM

Lsnd lie-tween trio and HS rnagnel and opening the circuit of iiatcly thereafter the switch H1 is 111011101!lfiillfl' LlUl: d and then opened by the action of hook l upon its blade, bhusmomcnt-arily ranmvetiug the local bat cry/across the mains A nae- C and energizing the wind ing of the pol zed circuit-breakerj. The winding of l: circnitbrcali'cr and no conncctions oi said battery are such that the armature f is attract thus not only relcasing the blade j and indicating to the central operator tl it a subsc: 'bcr calling. but also opening the switch of which saiiil blade forms a part. and consequently breaking what is practically a shortcircuit between mains A and .3. -"irsr". this movement; or the blade ,i"' or of die n tine f" may be made to operanairi'ol' h ll-hnown 'isnal orau-tlitor signals wi l Known in the arc, though since tlic pivot" l b .dc iiself is the equivalent f such 'i'carure of the invention i iis has nor or illustrated. the recon the icrmin;

n fur-t:

nd oi the llOOl-I 14; also connects oi' thc switch 3 in Fig: so as to throw if c ci cuii i-he transiniticr l and iinall, pair-mils the bar to mow: into engageincnt will! thrtrrininai 17. so as to place the rcccirr-r in circa r with main A. The central operator now plugs into the circuit by inserting thc upnralor-s plug or plugs in switch ix. thus pcrmitiing currajnit in flow from the lull? m H at the central station through the main 7 in ground and connects said opcric tors instrument. so that conversation Will.

(11101105 occur with llic magnet because of i Lhc 'n'crious mini-position of tho arm on lwcen its armature and the core, in each case when: Zho arthe bar be as ai oi'c not-ad.

-. ,4 :3 i uetsu n u cc. each iii the main l, all of the mag- 5 core lllQ incandescent lamp 6 or other form of visual or auditorysignal. is operated from the pl:i3'ocl'-. u each telephone instrument on the other than the one calling the central. L-er having been informed as to the numoi iihc rnlcphonc with which the calling subscriber desires connection the central operator inserts the second one of the plugs Y in t l one oi. the openings of the switch K which corresponds to llic number of the instru aent called for.

By inspection of the figures itv will be seen that the banks of resistance ll i F, 8:43., are so proportiiiined relatively to the two sets of windings on the various magnets w &c., that the current from the generator 12 flowing through wire 0 will divide between the mains A and C, so Lhat the field produced by one of tho windings on a certain magnet (1 or 4, connected bctwccn said lines, will neutralize than produced by the second winding upon said magnet -t-hat is to say, when the central operator has plugged into one of the openingsni, for example- --of switch K the on rrcnt from the g'cni'rrntor n will divide into two currcn'igs oii' prmlcrcrmincd strengths, so that the ctl'cctol the winding u uponflie magnet will be substantially neutralized by the cliect oi the winding Ii" upon said magnet. thereby causing no motion of the armature of this magnet. ()n the other hand. since the ratio to each other of the turns of rho two windings upon tho magnet 11 is diflcrenl: from that of the turns of the windings upon the magnet 17 the currents ilowing on the two mains arc not pro pcrly adjusted LO render said [Ill-lgnetu" inopcral-iwi. and it will cause motion of its armature. "llie result of such action is that the flow oi current through the main A cnern'izos the bell-cont-rolling magnets 1] of cach i'clcphouc instrument, so that said magnet-s are caused to move their armatures and close the swil'chcs Such closing oi said swiichcs will have no effect except in the case oi" the instrument which it is desired to call up -;i'i;:., that having the 1nagnctr,/---sincc the armature ll} of this; instrument is the only TIO " one which is in a position such that thorn is a complete circuitl'rom its local bz1lZl70l,V fC0 the bell ii and the bar 1. As a consequence tlic boll B is run; continuously until the rear oi' ulic instrument having the mag I is lifiad from its hook. which action, bv. temporarily connncriir the local battery f" bctwnou the lines and C, operates the pocircuit-brcalccr j at central. ihcrcby 125 larixcd also opening hlic circuit of main A", dccnergizing n'iagnc-L M. and opening the local bcll circuit. it will be noted that current from gliiililll l i l' 1: cannot actuate the polarized magthat the short-circuit connection between mains A and C is removed. The bells of the other telephone instruments, as D are not rung by the loEal battery f, because the windings of the magnets a in said instruments act together and move armatures 16 so as to break the bell-circuits, whereas when.

central-sends current to ring these windings are so arranged and connected as to act in opposition and neutralize each other.

It will be noted that as soon as current has been allowed to flow through the mains A and C by the central operator plugging in allof the telephone instruments other than the one called are rendered inoperative, since even though the receiver of one of these instruments be removed from its book there is no possibility of the bar2 of said instrument rising, since such motion is prevented by the armature 16 'of the magnet beinginterposedin the way of the arm 15. The lifting of the receiver 12 of the instrument called permits the hook 14 of said instrument to rise, as before noted, and by its action upon the blade of switch m temporarily connects the local battery f across the mains A and C, and thereby causes opening of the circuit-breaker 7'.

When the book 14 of the subscriber called is in its uppermost position, the circuit of main A is closed through said subscribers receiver, the transmitter being also connected so as to be operative, so that conversation can be successfully carried on between the subscribers using the instruments D and D. It will be noted that, as in the case of line in which is connected the instrument of the subscriber calling up, so with the line having the instrument D, all other instruments on the same line have automatically displayed a busy signal. This is due to the completion of the circuit through their respective incandescent lamps 6 by the action of magnets (4 &c.', upon the respective armatures 16 and bars 1, which throws the local batteries, f into circuit with said lamps.

Upon the receiver 12 of the instrument D being returned to its hook at the close of conversation thereceiver and then the transmitter-circuits are broken and the hook 14 momentarily opens the switch g, which, as before noted, is in the circuit of the main G. Since current flowed upon said main when the central operator first plugged in and again flows after the momentary opening of switch g, the escapement'of circuit-breaker b has been twice permitted to act, and thus caused to drop its bar it, indicating to central that the instrument D is no longer in use. The removal of the plugs Y from the switches K and K cuts oif generator 0 from the system and the various parts return to their normal positions, the bars j and if being returned to their set positions by-hand.

If the subscriber using the instrument D had wished to be connected to instrument D the central operator would have inserted plug Y in that one of the openings s.of switch K which would introduce suflicient resistance k &c., in line A to cause the current from generator n-to divide, so as to render the windings of magnet a inoperative upon their armature, while causing motion of all the other magnet-armatures operative on the same line.

Should the subscriber using instrument D desire to be connected with an instrument, as D on the same pair of linesA and C, the central operator would simply reinsert a plug Y in that one of the openings 8 of switch K which would cut an amount of, resistance into circuit with main A to cause the windings of said instrument D to neutralize each other, also closing switch 0, so as to permit current to flow around the .open circuitbreaker j.

If it be desired to prevent the possibility of a second subscriber'connecting 'his instrument on the line by removing his receiver from its hook during the brief interval elapsing between the making of a call and its answer by the central operator, I may .useconductors g and 19*, connected, respectively, to the plates 12 and q, as shown in Fig. 3. Said conductors have terminals 10 placed to be electrically connected by the bar j when this latter has been released by the movement of'the armature of the circuit-breaker 7'. With such an arrangement of parts current from .generator n is permitted to flow through main 0 as soon as a calling subscriber removes his receiver from its hook, thus effectually looking all the other telephone instruments on the same line even before the central operator has plugged in. l

I claim as my invention 1. A system including a two-conductor line grounded at one end, a plurality of telephones connected thereon, each provided with mechanism for rendering it inoperative-and each having a calling device, with means for simultaneously actuating the mechanism on certain of said telephones and for actuating the calling device of the remaining telephone only, said means having one terminal grounded, substantially as described. a

2. A system including two lines, aplurality of telephones connected thereon. each having a calling device and a magnet, each magnet being provided with two independent windings connected respectively in said lines, a set of mechanism controlled by each of said magnets for rendering inoperative one of the telephones and a selective switch for causing operation of all but a single one of said sets loo of mechanism and for causing actuation of the calling device of that telephone whose mechanism is not actuated, substantially as described.

A telephone system including a multiparty two-conductor line, each instrument on said multiparty-iine having mechanism for rendering it operative and a calling device, with apparatus for actuating said mechanism on certain of said telephones and for actuating the calling device of the remaining telephone, said apparatus including a magnet having diti'ercntial windings respectively connected in series with the conductorsot' the multiparty-line, substantially as described.

4. A telephone system including two conducting-lines in the samecircuit, a plurality of electrical instruments connected thereon, each provided with a locking device, including a differentially-wound magnet, an indicator and a calling device, with means having its terminals connected respectively to the ends of said lines for operating the calling device of any instrument and for actuating the indicators and the locking devices of the remaining instruments, substantially as described.

5. A telephone system including'twoconducting-lines on the same circuit, a plurality of telephone instruments connected thereon, each including a switch for controlling its operations, a loclting'de-vice for the switch including a ditierentially-wound magnet an indicator and a calling device, with means having its terminals connected respectively to the ends of said lines for operating the calling device of any instrument and for actuating the locking devices and the indicators of the remaining instruments, substantially as described.

6. A telephone system including a tw0-con ductor line, instruments connected thereto having magnets and armatures therefor, a switch in circuit with each receiver controlled by one of said armatures and means for causing any one of the magnets to become inoperative and simultaneously actuating the remaining magnets, said means having its terminals connected respectively to the ends of said line, with a calling device on each instrument controlled by the said magnet thereof, substantially as described.

7. A telephone system including instruments each having a circuit provided with a calling device and two switches, magnets havin armaturcs for respectively controlling said switches, and means for causing all but a predetermined one of said magnets to operate their switches, substantially as described.

8. A system including telephone instruments each having two non-polarized magmets, switches respectively controlled by said magnets, and a calling device in circuit with said switches, with means for energizing one magnet on all the instruments and the second magnet on all but one of said instruments, substantially as described.

9. A system including telephone instruments each having two magnets, a normally closed switch controlled by one magnet of each instrument, a normally open switch controlled by the second magnet of each instrument, calling devices in circuit with each pair of said switches and means for actuating the second magnet of each instrument and the first magnet on all but one of these instruments, sub stantially as described.

10. A system including telephone instruments each having two magnets, a normally closed and a normally open switch controlled by one magnet, an indicator in circuit with the normally open switch, a normally open switch controlled by the second magnet, acalling device in circuit with the closed switch of the first magnet and the switch controlled by the second magnet. with means for actuating one magnet of all the instruments and the second magnets in all the instruments but one, substantially as described.

11. A system including a central station, a plurality of telephone instruments on the same line, a circuit-breaker connected to said line at the central station, an indicator actuated by said circuit-breaker, and a current-generator for each instrument provided with means whereby it may actuate said circuit-breaker, substantially as. described.

12. A system including a central station, a plurality of telephone instruments on the same line, and acircuit-breaker including an indicator connected to said line at the central station, each instrument having a current-generator, a normally open switch and means for temporarily closing the same on each in strument, substantially as described.

'13. A system including a central station, a plurality of telephone instruments on the same line, a polarized circuit-breaker and indicating means operatively connected to said line at the central station, a current-generator, a normally open switch and means for temporarily closing the same on each instrument, with a current-generator at the central station ,and mechanism for each instrument actuated the lines and the second being interposed between the lines and the main current-generator, substantially as described. 7

16. A system including a central station, a main current-generator, conducting-lines having telephone instruments each provided with a current-generator and a switch with two automatic circuitbreakers at the central station, oneof the same being polarized and connected between the lines and the second being-interposed between said lines and the main current-generator, substantially as described.

17 A system including a central station, a

- main current-generator, conducting-lines having telephone instruments each provided With a current-generator and a switch with two automatic circuit-breakers at the central station, one of. the same being connected between the lines, the second being interposed between said lines and the main current-generator, and having escapement mechanism whereby it is required to be twice energized before it will operate, substantially as described.

18. A system includ ing a current-generator, a circuit-breaker having escapement mechanism requiring a plurality of flows of current before it permits the circuit-breaker to open, with telephone instrumentselectrically connected to said circuit-breaker, substantially as described.

19. A system including a current-generator and a circuit-breaker having mechanism requiring two-flows of current before it permits the breaker to open,'with a series of telephoneinstruments electrically connected to said circuit-breaker, each having a normally closed switch in circuit with the same and means for opening said switch, substantially as described.

20. A system including a current-generator, a switch and a circuit-breaker having mechanism requiring a plurality of current-flows for its operation, with a series of telephone instruments, each having a receiver, a hook therefor, a normally closed switch and means operated by motion of the receiver-hook for temporarily opening the same, substantially as described.

.21. "A telephone system including instruments having a double-Wound magnet, an armature therefona receiverand a book therefor, a piece'controlled by the receiverhook .and movable to prevent motion of said armature, with a calling device including a switch controlled by the armature, substantially as described.

22. A telephone system including instruments each having a double-wound magnet,

an armature therefor, a receiver and a hook therefor,- a piece controlled by the receiverhook and movable to prevent motion of said,

armature, with calling and indicatiug'devices including switches, controlled by the armature, substantially as described. I

23. A system including two lines, a series of telephones connected between said lines,

and each havinga receiver and a hook there- WILLIAM R. WHITEHORNE.

Witnesses: 7

WILLIAM E. BRADLEY, Jos. H. KLEIN. 

